2025/12/10 by J. F. Parisi, J. Schwartz, Parisi, J. F. +7
Physics and Astronomy · Materials Science · #Fusion and Plasma Physics Studies #Magnetic confinement fusion research #Fusion materials and technologies
paper · pdf · doi:10.48550/arxiv.2512.09242
Fusion systems producing isotopes via neutron-driven transmutation can achieve economic viability well before reaching energy breakeven. Incorporating carefully selected feedstock materials in a blanket allows fusion systems to generate both electrical power and high-value isotopes, expanding the space of viable concepts, significantly enhancing the economic value of fusion energy, and supporting an accelerated path to adoption. We calculate the value of this co-generation and derive a new economic breakeven condition based on net present value. At lower plasma gain, Qplas\lesssim 1, high-value transmutation, such as medical radioisotopes, enables pure transmuter fusion systems operating at only watts to megawatts of fusion power: for example, a 3 megawatt system transmuting 102Ru→99Mo could fulfill global 99Mo demand with Qplas ≪ 1. At higher gain Qplas\gtrsim 3, it becomes viable to generate electricity in addition to isotopes. For example, co-production of electricity and gold, transmuted from mercury in a fusion blanket, can reduce the required plasma gain for economic viability from Qplas∼ 10-100 to Qplas∼ 3-5. We further highlight techniques to enhance transmutation with asymmetric neutron wall loading. Fusion neutron-driven transmutation therefore offers a revenue-positive pathway for deploying fusion energy at terawatt-scale, starting from smaller watt-to-megawatt-scale machines for radioisotope production and then scaling up to co-producing electricity and gold in larger fusion power plants.